DESCRIPTION (Applicant's Description Verbatim): Angiogenesis or blood vessel formation is necessary for tumor growth; its inhibition is, therefore, an excellent target for cancer therapy. The inherent complexities of current animal models, however, complicate screening of compounds for antiangiogenic activity. Using zebrafish (Danio rerio) embryos, this SBIR proposal aims to develop a quantitative, microplate enzyme assay for assessing vessel development. Zebrafish is an ideal whole animal model for drug screening because embryos can be generated and maintained inexpensively and are amenable to automated analysis. Drug delivery is simple, and drug and toxicity effects are easily detected because the embryos are transparent. Rapid embryonic development also facilitates rapid detection of drug effects. Preliminary studies indicate good correlation between quantitative results obtained using the enzyme assay and qualitative results obtained using microscopy. Phase I research will also assess key parameters for automating the enzyme assay and evaluate other proteins as potential markers for more specific angiogenic effects in zebrafish. PROPOSED COMMERCIAL APPLICATION: By providing a rapid, high throughput, automated method for screening drugs, the zebrafish assay will help to steamline the durg development process for cancer and heart disease. In 1997 the worldwide market for drug screens for cancer and heart disease was $500M.